You're better off aliasing than using a variable, but perhaps adding a notify task to a generic Makefile that calls growlnotify when the install task finishes is another option - you can then use that in subsequent Makefiles via an include.

+Carmelyne Thompson Yeah, it seems to be the best, least effort solution right now. Discussing the idea further, it could monitor background processes that are on a whitelist (or not on a blacklist), otherwise tools like top, etc would give you an alert when you don't really want one.

+Sasha Gerrand The problem for me with the aliasing solution is that I'm running various commands (e.g. cat, sort, find, etc) which are occasionally piped through various other commands. That's why I ended up with the "variable" solution so that I can choose to add when I want an alert.

+Gerald Kaszuba There is merit with +David Turnbull's idea of hooking into the shell, (e.g. capturing the output of $(ps rT o pid) and filtering the process name against a whitelist). I fear that it'd be no easy task though.